The New York Times reports on Yu Darvish’s comments to the Japanese media last week about arm injuries and stuff. Upshot: he’s all for a six-man rotation:

. . . Darvish said he believed that a shift to a six-man rotation by major league teams could significantly reduce the stress on all those elbow ligaments by giving pitchers a critical extra day to rest and limiting their starts . . . Speaking to Japanese reporters in Minneapolis last week, he said, “If you really want to protect players, we should add one more spot to the starting rotation.”

He got some backup from teammate Colby Lewis who spent two years in Japan and was used to the once-a-week pitching schedule (Japanese teams play six days a week and have six-man rotations).

Eh. Could it reduce pitcher injuries? It’s possible. There is some, albeit no definitive evidence that elbow injuries are less frequent in Japan. But there are also tradeoffs in terms of (a) giving less effective pitchers more innings; and (b) requiring teams to devote yet another roster spot to a pitcher. This in an age when teams are already frequently playing games with only two position players on the bench plus a backup catcher they won’t use unless they’re forced to. Sure, ideally you’d think teams would get rid of a reliever for an extra starter, but when was the last time a manager gave up a reliever even when it made sense? Heck, they’d sooner play infielders in the outfield than get rid of that 13 or 14-man pitching staff/security blanket.

There would have to be major roster rules changes to accompany such a thing, as they have in Japan. There rosters are 28-men deep instead of 25 and a couple of players are activated/deactivated on a game-by-game basis. If you do that here maybe it helps, but it still doesn’t solve the problem of using a guy who, today, couldn’t crack your rotation as a once-a-week starter.

If the injury/start frequency evidence got more definitive, sure, you do what you do in order to save your resources. But until then it’s a pretty tall cost to go with a six-man rotation on the regs.